Coca-Cola Controversy: Is Exercising More or Eating Less Better for Weight Loss?

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Coca-Cola has given a million dollars to a new research
organization that has pushed a message that lack of exercise is a
bigger factor in the obesity epidemic than is calorie
consumption. Science, however, still counts calories as the main
driver of weight gain for most people.

Although exercise makes people healthier, cutting calories
usually plays a bigger role in
weight loss, experts say.

"There's an overwhelming amount of research demonstrating that,
from an individual perspective, the key is decreasing calories
modestly to successfully lose weight over time," said Dr. Pieter
Cohen, an assistant professor of medicine at Harvard Medical
School. "It's certainly great to add exercise, but to suggest
that it's the solution to the obesity epidemic … is ridiculous,"
Cohen told Live Science. [ Lose
Weight Smartly: 7 Little-Known Tricks That Shave Pounds ]

The new nonprofit organization, called the Global Energy Balance
Network (GEBN), received $1.5 million from Coca-Cola last year to
help launch the organization,
according to The New York Times. (Energy balance means
consuming as many calories as you burn to maintain weight.)

In a
statement, Steven Blair, a professor of exercise science at
the University of South Carolina Arnold School of Public Health
and a member of GEBN, said that although the media have focused
on "blaming fast food" and sugary drinks for the obesity
epidemic, "there's really virtually no compelling evidence that
that, in fact, is the cause."

On its website, the GEBN does not deny that good health involves
both eating a healthy diet and doing exercise. But the
organization's website also
says there is "strong evidence that it is easier to
sustain at a moderate to high level of physical activity
(maintaining an active lifestyle and eating more calories)" than
it is to be sedentary and eat fewer calories. In an
editorial published in 2014, several members of GEBN wrote
that increasing physical activity "may be more achievable than
reducing [calorie] intake" for energy balance.

An exercise program by itself typically doesn't lead to much, if
any, weight loss, Cohen said. One reason for this is that
exercise increases appetite, which can lead people to eat more,
Cohen said. Exercise also causes the body to produce more muscle,
which is heavier than fat tissue.

In addition, it's usually easier to cut
calories out of the diet than it is to exercise at the
levels needed to burn enough calories for weight loss.

For example, in general, experts say a person needs to cut 500
calories a day from his or her diet to lose 1 lb. (0.45
kilograms) a week. In theory, it would be possible to burn 500
calories through exercise instead of caloric restriction, Cohen
said. But this would be difficult, because burning this amount of
calories through exercise takes time, and in order for the
strategy to work, people could not consume a single calorie more
than they do already, despite their increased activity.

"It would be much easier to eliminate those 500 calories [from
our diet] than to find the time to exercise enough to burn 500
calories a day," Cohen said. As an example, a 155-lb. (70 kg)
person would have to run for about 50 minutes at 5 mph (8 km/h),
a 12-minute-mile pace; or walk for 100 minutes at 3.5 mph (5.6
km/h), a 17-minute-mile pace; to burn 500 calories, according to
information from
Harvard University Medical School.

However, James O. Hill, president of GEBN and a professor at the
University of Colorado School of Medicine, said that the
suggestion that GEBN promotes exercise as more important than
diet in addressing obesity "vastly oversimplifies this complex
issue."

"Diet is a critical component of weight control, as are exercise,
stress management, sleep, and environmental and other factors,"
Hill said in a statement. "The problem does not have a single
cause and cannot be addressed by singling out only one of those
factors in the solution," said Hill, who added that research from
GEBN is not subject to pre-approval from Coca-Cola.

But advice from the Mayo Clinic also supports the view that diet
is more important than exercise when it comes to shedding the
pounds. "Cutting calories through dietary changes seems to
promote weight loss more effectively than does exercise and
physical activity," Dr. Donald Hensrud
wrote in a column for Mayo Clinic. "For most people, it's
possible to lower their calorie intake to a greater degree than
it is to burn more calories through increased exercise."

But Cohen stressed that exercise should still be part of a
weight-loss program. When people exercise, they create more
muscle, which helps boost metabolism. Researchers think that this
increase in metabolism helps people maintain the weight they've
lost, Cohen said.